1 files changed, 100 insertions, 0 deletions
diff --git a/mpi/arm/mpih-mul3.S b/mpi/arm/mpih-mul3.S
new file mode 100644
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+++ b/mpi/arm/mpih-mul3.S
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+/* ARM mul_3 -- Multiply a limb vector with a limb and subtract the result
+ *              from a second limb vector.
+ *
+ *      Copyright © 2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgcrypt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Note: This code is heavily based on the GNU MP Library (version 4.2.1).
+ */
+
+#include "sysdep.h"
+#include "asm-syntax.h"
+
+.syntax unified
+.arm
+
+/*******************
+ * mpi_limb_t
+ * _gcry_mpih_submul_1( mpi_ptr_t res_ptr,	%r0
+ *		     mpi_ptr_t s1_ptr,		%r1
+ *		     mpi_size_t s1_size,	%r2
+ *		     mpi_limb_t s2_limb)	%r3
+ */
+
+.text
+
+.globl _gcry_mpih_submul_1
+.type  _gcry_mpih_submul_1,%function
+_gcry_mpih_submul_1:
+	push	{%r4, %r5, %r6, %r8, %r9, %r10, %lr};
+	mov	%lr, #0;
+	cmp	%r0, #0; /* prepare carry flag for sbc */
+
+	tst	%r2, #3;
+	beq	.Large_loop;
+.Loop:
+	ldr	%r5, [%r1], #4;
+	mov	%r4, %lr;
+	mov	%lr, #0;
+	ldr	%r6, [%r0];
+	umlal	%r4, %lr, %r5, %r3;
+	sub	%r2, #1;
+	sbcs	%r4, %r6, %r4;
+	tst	%r2, #3;
+	str	%r4, [%r0], #4;
+	bne	.Loop;
+
+	teq	%r2, #0;
+	beq	.Lend;
+
+.Large_loop:
+	ldr	%r5, [%r1], #4;
+	mov	%r9, #0;
+	ldr	%r4, [%r0, #0];
+
+	umlal	%lr, %r9, %r5, %r3;
+	ldr	%r6, [%r0, #4];
+	ldr	%r5, [%r1], #4;
+	sbcs	%r4, %r4, %lr;
+
+	mov	%lr, #0;
+	umlal	%r9, %lr, %r5, %r3;
+	ldr	%r8, [%r0, #8];
+	ldr	%r5, [%r1], #4;
+	sbcs	%r6, %r6, %r9;
+
+	mov	%r9, #0;
+	umlal	%lr, %r9, %r5, %r3;
+	ldr	%r10, [%r0, #12];
+	ldr	%r5, [%r1], #4;
+	sbcs	%r8, %r8, %lr;
+
+	mov	%lr, #0;
+	umlal	%r9, %lr, %r5, %r3;
+	sub	%r2, #4;
+	sbcs	%r10, %r10, %r9;
+
+	teq	%r2, #0;
+	stm	%r0!, {%r4, %r6, %r8, %r10};
+	bne	.Large_loop;
+
+.Lend:
+	it	cc
+	movcc	%r2, #1;
+	add	%r0, %lr, %r2;
+	pop	{%r4, %r5, %r6, %r8, %r9, %r10, %pc};
+.size _gcry_mpih_submul_1,.-_gcry_mpih_submul_1;